the short answer is no, but just to be sure you may want to overclock the cpu anyway
the in depth answer would be that the games you play wont be very intensive. if you play crysis or battlefield from time to time, the bottlneck (if there is one) will be too small to be a problem. so you have nothing to worry about.
now if you were using a 780 or 290x instead of the 270x, thats where you would have bottlenecking problems with this processor.